Cod sursa(job #2782975)

Utilizator Albert_GAlbert G Albert_G Data 13 octombrie 2021 16:37:57
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.9 kb
#include <fstream>
#include <queue>
#include <vector>

std::ifstream in("bfs.in");
std::ofstream out("bfs.out");

const int N = 1e5+1;
int dist[N];
std::queue<int> q;
std::vector<int> g[N];
int n,m,s;

void bfs(int source){
    dist[source] = 0;
    q.push(source);
    while (!q.empty()){
        int currNode = q.front();
        q.pop();
        for(auto node : g[currNode]){
            if(dist[node] == -1){
                q.push(node);
                dist[node] = 1 + dist[currNode];
            }
        }
    }
    
}

void initializeDist(){
    for(int i=1;i<=n;++i)
        dist[i] = -1;
}

int main(){
    in>>n>>m>>s;
    for(int i=0;i<m;++i){
        int a,b;
        in>>a>>b;
        g[a].push_back(b);
    }
    initializeDist();
    bfs(s);
    for(int i = 1;i <= n;++i){
        out<<dist[i]<<' ';
    }
    out.close();
    in.close();
    return 0;
}